Table 1.

The activities of tetracyclines against recombinant E. coli expressing major tetracycline-specific resistance mechanisms

	MIC (μg/mL)
	E. coli lacZ	E. coli tet(M)	E. coli tet(K)	E. coli tet(A)	E. coli tet(B)	E. coli tet(X)
Eravacycline	0.063	0.063	0.031	0.25	0.063	4
Tigecycline	0.063	0.13	0.063	1	0.063	2
Doxycycline	2	64	4	32	32	16
Minocycline	0.5	64	1	8	16	4
Tetracycline	2	128	128	>128	>128	128
Ceftriaxone	0.063	0.13	0.063	0.13	0.13	0.13

Genes were overexpressed in E. coli DH10B from a recombinant expression vector under the control of an arabinose promoter. Standardized MIC assays were performed according to CLSI methodology as previously described.

MIC, minimal inhibitory concentration; tet(M), ribosomal protection; tet(K), Gram-positive tetracycline efflux; tet(A) and tet(B), Gram-negative efflux; tet(X), flavin-dependent monooxygenase.

Data is reprinted, with permission, from Grossman et al. (2012).